Balancing apparatus for elevator

ABSTRACT

A balancing apparatus includes a frame body ( 1 ), a first weight ( 2 ) and a second weight ( 3 ) separated from each other vertically in the frame body ( 1 ). The first weight ( 2 ) is connected to the frame body ( 1 ) through elastic bodies ( 41, 42 ). The elastic bodies ( 41, 42 ) are always subjected to compression load. The first and second weights ( 2, 3 ) are accommodated together in the frame body ( 1 ). Since tensional load is not applied to the elastic bodies ( 41, 42 ), the durability of the balancing apparatus can be ensured.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to the improvement of a balancing methodfor an elevator.

2. Background Art

In a rope type elevator where an elevator car moves up and down througha main rope wound around a drive sheave, oscillations and vibrations ofthe car cause the ride quality for passengers to deteriorate.

Until now, various contrivances have been attempted in order to reducesuch oscillations and vibrations. For instance, the elevator car isprovided with an antivibration apparatus for reducing vibrations in thecar.

In the rope type elevator, generally, the elevator car is connected to abalance weight through the main rope. In view of the fact thatoscillations and vibrations are transmitted to the car through the mainrope, a reduction in oscillations and vibrations of the balance weightare indispensable for an improvement in the ride quality for passengersin the elevator car. Consequently, there has been proposed variousmeasures to reduce the oscillations and vibrations of the balanceweight.

A variety of reasons are presumed why such oscillations and vibrationsof the balancing apparatus (balance weight) are produced.

Although there is the case in that a change in the weight of the caritself, namely, its load change is transmitted to the balancingapparatus to cause its oscillations and vibrations, the balancingapparatus may oscillate and vibrate due to rotational vibrations of thedrive sheave in the traveling course of an elevator, oscillations of themain rope itself, slight expansion movement of the main rope in thelongitudinal direction and so on.

Additionally, in a rope type elevator that adopts so-called “one to one(1:1)” roping arrangement, a compensating rope (balancing rope) isinterposed between the car and the balancing apparatus, so, oscillationsof such a compensating rope may cause the balancing apparatus tooscillate or vibrate.

In any case, as oscillation or vibrations of the balancing apparatuscause the elevator car to vibrate through the intermediary of the mainrope, it is required to reduce such oscillation or vibrations of thebalancing apparatus.

In order to reduce oscillation or vibrations of the balancing apparatus,Japanese Patent Application Laid-open (Heisei) No. 6-100273 proposes abalancing apparatus as shown in FIG. 1.

In this balancing apparatus, a frame body is divided into a first framebody 1A accommodating a first weight 2 and a second frame body 1Baccommodating a second weight 3. The first frame body 1A is connected tothe second frame body 1B through elastic bodies 41, 42 (e.g. springs)and a damper 5 juxtaposed to each other. The first frame body 1A is alsoconnected to a plurality of main ropes 7 through corresponding shacklerods 6, while the second frame body 1B is connected to compensatingropes 8.

In the balancing apparatus, the elastic bodies 41, 42 and the damper 5do constitute a dynamic vibration absorber for suppressing vibrations ofthe balancing apparatus.

However, the above-mentioned balancing apparatus is complicated instructure due to the existence of the frame bodies 1A, 1B in separation.

Additionally, although the elastic bodies 41, 42 and the damper 5forming the dynamic vibration absorber exhibit superior durability forwithstanding compression load, they exhibit inferior durability forwithstanding successive tensional loads.

That is, in the disclosed balancing apparatus where the elastic bodies41, 42 and the damper 5 suspend the lower frame body 1B containing thesecond weight 3 and also the compensating ropes 8, the dynamic vibrationabsorber is usually subjected to tensional loads. Consequently, there isa possibility that the dynamic vibration absorber deteriorates infunction in process of time.

DISCLOSURE OF INVENTION

In the above-mentioned situation, it is an object of the presentinvention to provide a balancing apparatus for an elevator, which has asimple structure for suppressing vibrations of the balancing apparatusand a dynamic vibration absorber whose function can be maintained inspite of the passage of time.

In order to achieve the above-mentioned object, according to the firstaspect of the present invention, a balancing apparatus for an elevatorhaving an elevator car for passengers, comprises: a frame body connectedto the elevator car through a main cable; and a balancing weightaccommodated in the frame body, the balancing weight having a firstweight and a second weight separated from each other vertically in theframe body, wherein the first weight is positioned above the secondweight and is supported by the frame body through a dynamic vibrationabsorber under the first weight.

In the balancing apparatus of the first aspect, since the first weightis connected to the frame body through at least the dynamic vibrationabsorber, it is always subjected to not tensional loads but compressionload.

Accordingly, the durability of the dynamic vibration absorber can bemaintained in spite of the process of time. Additionally, since thefirst weight and the second weight are accommodated together in thesingle frame body, the structure of the balancing apparatus issimplified and the arrangement of the first and second weights can bemaintained irrespective of the durable change of the dynamic vibrationabsorber.

According to the second aspect of the invention, in the above balancingapparatus, the dynamic vibration absorber includes at least one elasticbody.

Then, the dynamic vibration absorber is simplified in structure.

According to the third aspect of the invention, in the above balancingapparatus of the second aspect, the dynamic vibration absorber furtherincludes a damper.

Then, owing to the addition of the damper, the dynamic vibrationabsorber is enhanced in absorbing vibrations of the balancing apparatus.

According to the fourth aspect of the invention, in the above balancingapparatus of the second aspect, the dynamic vibration absorber includesupper and lower elastic bodies between which the first weight isinterposed, and the first weight is connected to the frame body throughthe upper elastic body.

In the above arrangement, since both of the upper and lower elasticbodies are subjected to compression load, the durability of the dynamicvibration absorber can be maintained in spite of the process of time.

According to the fifth aspect of the invention, in the above balancingapparatus of the fourth aspect, the dynamic vibration absorber furtherincludes a damper juxtaposed to the upper elastic body.

Then, owing to the addition of the damper, the dynamic vibrationabsorber is enhanced in absorbing vibrations of the balancing apparatus.

According to the sixth aspect of the invention, the balancing apparatusof the second aspect further comprises a sheave rotatably arranged inthe frame body, wherein the first weight is connected to the sheave, andeither the sheave or the first weight is connected to the frame bodythrough the elastic body arranged on the sheave or the first weight.

With the arrangement mentioned above, since the elastic body issubjected to compression load, the durability of the dynamic vibrationabsorber can be maintained in spite of the process of time.

According to the seventh aspect of the invention, the balancingapparatus of the third aspect further comprises a sheave rotatablyarranged in the frame body, wherein the first weight is connected to thesheave, and either the sheave or the first weight is connected to theframe body through the elastic body arranged on the sheave or the firstweight and the damper juxtaposed to the elastic body.

Also in this case, owing to the addition of the damper, the vibrationabsorbing function of the dynamic vibration absorber can be enhanced.

According to the eighth aspect of the invention, in the balancingapparatus of the first aspect to the seventh aspect, at least one of thefirst weight or the second weight is formed by a lamination of weightmembers.

Then, by changing the number of weight members, the first weight or thesecond weight can be modified in terms of weight.

According to the ninth aspect of the invention, the balancing apparatusof the first aspect to the eighth aspect further comprises a slidemember or a rotating member interposed between the frame body and thefirst weight and movable either up or down due to expansion andcontraction of the dynamic vibration absorber.

Then, owing to the interposition of the slide member or the rotatingmember, the first weight can slide in the frame body with noinclination.

These and other objects and features of the present invention willbecome more fully apparent from the following description and appendedclaims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a structural view of a conventional balancing apparatus;

FIG. 2 is a structural view of a balancing apparatus in accordance withthe first embodiment of the present invention;

FIG. 3 is a sectional view taken along a line 3-3 of FIG. 2;

FIG. 4 is a structural view of the balancing apparatus of FIG. 1,showing an arrangement adopting other fixing elements;

FIG. 5 is a structural view of the balancing apparatus of FIG. 1,showing a state where the vertical arrangement of the first and secondweights is reversed;

FIG. 6 is a structural view of a balancing apparatus in accordance withthe second embodiment of the present invention; and

FIG. 7 is a structural view of a balancing apparatus in accordance withthe third embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIGS. 2 to 7, embodiments of the present invention will bedescribed below. Note, that elements identical to those of theconventional balancing apparatus of FIG. 1 are indicated with the samereference numerals respectively.

FIG. 2 is a structural view of a balancing apparatus applied to aone-to-one roping type elevator. FIG. 3 is a sectional view taken alonga line 3-3 of FIG. 2.

According to the first embodiment, the balancing apparatus includes oneframe body 1, first and second weights 2, 3 both accommodated in theframe body 1 vertically, elastic bodies 41, 42 and a damper 5 allinterposed between the first weight 2 and the second weight 3.

As shown in FIG. 2, each of the first and second weights 2, 3 contains aplurality of plate-shaped weight members, such as metal plates, stackedupon each other. The elastic bodies 41, 42 are formed together byelastic members, for example, coil springs, rubbers and so on.

The elastic bodies 41, 42 and the damper 5, which are juxtaposedhorizontally to form a dynamic vibration absorber, are positioned on thesecond weight 3 to support the first weight 2 thereon. The second weight3 is fixed onto the frame body 1. Thus, the elastic bodies 41, 42 andthe damper 5 are adapted so as to support a load of the first weight 2and are always subjected to compressive pressure.

In the one-to-one roping type elevator shown in the figure, the framebody 1 is suspended from main ropes 7 through shackle rods 6, whiledynamic vibration absorber compensating ropes 8 drag a lower part of theframe body 1 downwardly due to their own weights.

The above-constructed balancing apparatus operates as follows.

If the balancing apparatus oscillates or vibrates by various causes(e.g. oscillations or vibrations of the car or the main ropes 7,rattling movement of a not-shown drive sheave in rotation occurs,causing a slight expansion and contraction of the main ropes 7, etc.),then the first weight 2 vibrates vertically. However, as the elasticbodies 41, 42 and the damper 5 forming the dynamic vibration absorberfunction to absorb or suppress such vibrations of the first weight 2,vibrations of the whole balancing apparatus is alleviated, so thatvibrations of the car can also be suppressed.

As shown in the figure, the first weight 2 is formed by a lamination ofmetal plates. In order to maintain such a lamination in spite ofvibrations of the first weight 2 itself, it is secured by fixingelements 9. Each of the fixing element 9 is a type of securing unithaving a bolt 9 a penetrating the first weight 2 and a nut 9 b in threadengagement with the bolt 9 a.

According to the first embodiment, as shown in FIG. 3, the first weight2 swinging vertically is provided, on all sidewalls thereof, with slidemembers 10 in the form of triangular pyramids. These slide members 10are arranged in a manner that their respective tips come in soft contactwith the inside wall of the frame body 1. With the arrangement of theslide members 10, the first weight 2 is capable of smoothly sliding inthe vertical direction with no inclination while being guided by theframe body 1. That is, when the whole balancing apparatus vibrates andconsequently, the first weight 2 oscillates up and down in a directionto cancel the vibrations of the balancing apparatus, the first weight 2is capable of stable movement in the vertical direction without beinginclined

Note that in the balancing apparatus, its frequency and amplitude ofvibration is generally determined by the lengths of the main ropes 7between the drive sheave and the balancing apparatus and its weight(mass) thereof. Meanwhile, in the balancing apparatus of the firstembodiment, when the apparatus itself vibrates, the dynamic vibrationabsorber formed by the elastic bodies 41, 42 and the damper 5 functionsto cancel vertical oscillation of the first weight 2, that is, itsvibration. Therefore, it is possible to avoid the occurrence ofunnecessary secondary vibration of the apparatus itself.

With regard to the weight ratio of the first weight 2 to the wholeweights, respective spring constants of the elastic bodies 41, 42 andthe damper 5 and their elastic coefficients, there are selectedappropriate values that allow the vibration frequency, which has thelargest energy in the vibration mode of the whole balancing apparatus,to be absorbed or restricted within a wider frequency range effectively.

Additionally, according to the first embodiment, as the first weight 2is formed by a lamination of metal plates etc., it is possible toproperly select a ratio of the first weight 2 to the whole weight inview of more effective antivibrating or damping action.

As mentioned above, the balancing apparatus of the first embodiment hasa simple structure where the first and second weights 2, 3 are arrangedup and down in the single frame body 1 while interposing the juxtaposedelastic bodies 41, 42 and the damper 5 therebetween. Furthermore, theelastic bodies 41, 42 and the damper 5 are always subjected tocompressive load due to the first and second weights 2, 3. Accordingly,it is possible to afford a high level of safety and appropriatedurability for the elevator.

Note that although the fixing element 9 is formed by the bolt 9 a andthe nut 9 b in the first embodiment, the constitution may be modified asshown in FIG. 4. In this modification, the fixing element 9 is formed bya U-shaped retainer attachment 9 c, a pusher screw rod 9 d penetratingthe upper end of the retainer attachment 9 c and a pair of nuts 9 e, 9 efor fixing the rod 9 d on the upper end of the retainer attachment 9 c.

The arrangement where the elastic bodies 41, 42 and the damper 5 arearranged on the second weight 3 may be modified. It follows that asimilar effect can be expected if only arranging the elastic bodies 41,42 and the damper 5 on a structure integral with the frame body 1. Inthe modification shown in FIG. 5, the elastic bodies 41, 42 and thedamper 5 are mounted on the inside bottom wall of the frame body 1directly. With this arrangement, the second weight 3 is arranged abovethe first weight 2 and also fixed to the frame body 1 through attachmentelements 3 a, 3 a.

The second embodiment will be described with reference to FIG. 6.

The following descriptions are directed to differences in the secondembodiment from the first embodiment of FIGS. 2 to 5.

In the balancing apparatus of FIG. 6, the above first weight 2 isdivided into two group of weights from side to side. That is, firstweights 21, 22 are arranged so as to avoid the shackle rods 6 at thecenter of the upper part of the frame body 1. Being interposed between afirst elastic body 41 a and a second elastic body 41 b in the verticaldirection, the first weight 21 is connected to the frame body 1 throughthe first elastic body 41 a. Similarly, being interposed between anotherfirst elastic body 42 a and another second elastic body 42 b in thevertical direction, the first weight 22 is connected to the frame body 1through the first elastic body 42 a. The first elastic bodies 41 a, 42 aand the second elastic bodies 41 b, 42 b are always subjected topressures from the frame body 1 and the first weights 21, 22.

For the above arrangement, two bolts 11 a, 11 a are arranged so as topenetrate the first weights 21, 22 and the frame body 1. On the upperpart of the frame body 1, nuts 11 b, 11 b are fastened to the bolts(parts) 11 a, 11 a projecting from the frame body 1.

Further, dampers 51, 52 forming the dynamic vibration absorber arearranged in parallel with the first elastic bodies 41 a, 42 a,respectively. Between the first weights 21, 22 and the frame body 1, thedampers 51, 52 are also subjected to pressures.

Thus, also in the second embodiment, the first and second weights 21,22, 3 are arranged up and down in the frame body 1. Further, the elasticbodies 41 a, 41 b, 42 a, 42 b and the dampers 51, 52, which form thedynamic vibration absorber are always under pressure, function to absorbor suppress vibrations of the first weights 21, 22 vibrating inassociation with the vertical vibration of the apparatus itself. Owingto such an operation of the apparatus, it is possible to restrict thevibration of the whole apparatus effectively and stably.

Although no slide member is provided on opposing sidewalls of the firstweight 21, 22 of the second embodiment, the bolts 11 a, 11 a penetratingthe weights 21, 22 are fixed to the frame body 1 in alternation.Therefore, it is possible to prevent the first weights 21, 22 fromoscillating from side to side largely.

Here, note that the first and second embodiments are commonly related tothe balancing apparatus for a rope type elevator adopting a one-to-one(1:1) roping arrangement. Additionally, the present invention isapplicable to a rope type elevator adopting two-to-one (2:1)arrangement.

Accordingly, FIG. 7 shows the third embodiment where the balancingapparatus is applied to such an elevator adopting a two-to-one (2:1)arrangement.

According to the third embodiment, the frame body 1 is provided,therein, with a sheave 12 around which the main rope 7 is wound. Thesheave 12 is rotatably supported by a plate 12 a. The first weights 21,22 similar to those of the second embodiment are fixed onto the lowersurface of the plate 12 a through the fixing elements 9, symmetrically.

Similar to the second embodiment, the first and second weights 41 a, 42a are disposed between the upper surface of the plate 12 a and the upperpart of the frame body 1, corresponding to the first weights 21, 22respectively. Additionally, the dampers 51, 52 are juxtaposed to theelastic bodies 41 a, 42 a, respectively. The dynamic vibration absorberis formed by the elastic bodies 41 a, 42 a and the dampers 51, 52.

Also in the third embodiment, the first and second weights 21, 22, 3 arearranged up and down in the frame body 1. Further, since the firstweights 21, 22 are adapted so as to always apply pressure onto theelastic bodies 41 a, 42 a and the dampers 51, 52, it is possible toaccomplish stable vibration-absorbing and damping effects, similar tothe first and second embodiments.

In the modification, so long as the first weights 21, 22 form one bodywith the plate 12 a, these weights 21, 22 may be mounted on the uppersurface of the plate 12 a. In such a case, the dynamic vibrationabsorber is arranged between the first weights 21, 22 and the frame body1.

In common with the above-mentioned embodiments, the dynamic vibrationabsorber is formed by the elastic bodies 41, 41 a, 41 b, 42, 42 a, 42 band the dampers 5, 51, 52. Alternatively, upon deletion of the dampers,the dynamic vibration absorber may be formed by the elastic bodies 41,42 (or 41 a, 42 a) only although the range of frequency of absorbedvibration is somewhat lessened.

Additionally, so long as the first weight 2 is allowed to oscillatevertically and smoothly, the above slide members 10 may be formed byrectangular solids in place of triangular pyramids in the shownembodiments. Alternatively, for the same reason, rotatable wheels (notshown) in place of the slide members 10 may be attached to either theframe body 1 or the first weight 2.

Finally, it will be understood by those skilled in the art that theforegoing descriptions are nothing but three embodiments of thedisclosed balancing apparatus and therefore, various changes andmodifications may be made within the scope of the claims.

INDUSTRIAL APPLICABILITY

In the balancing apparatus of the present invention, since the firstweight is connected to the frame body through at least the dynamicvibration absorber, it is always subjected to not tensional loads butcompression load. Accordingly, the durability of the dynamic vibrationabsorber can be maintained in spite of the process of time.Additionally, as the first weight and the second weight are accommodatedtogether in the single frame body, the structure of the balancingapparatus is simplified and the arrangement of the first and secondweights can be maintained irrespective of the durable change of thedynamic vibration absorber.

1. A balancing apparatus for an elevator having an elevator car forpassengers, comprising: a frame body connected to the elevator carthrough a main cable; and a balancing weight accommodated in the framebody, the balancing weight having a first weight and a second weightseparated from each other vertically in the frame body, wherein thefirst weight is positioned above the second weight and is supported bythe frame body through a dynamic vibration absorber under the firstweight.
 2. The balancing apparatus of claim 1, wherein the dynamicvibration absorber includes at least one elastic body.
 3. The balancingapparatus of claim 2, wherein the dynamic vibration absorber furtherincludes a damper.
 4. The balancing apparatus of claim 2, wherein thedynamic vibration absorber includes upper and lower elastic bodiesbetween which the first weight is interposed, and the first weight isconnected to the frame body through the upper elastic body.
 5. Thebalancing apparatus of claim 4, wherein the dynamic vibration absorberfurther includes a damper juxtaposed to the upper elastic body.
 6. Thebalancing apparatus of claim 2, further comprising a sheave rotatablyarranged in the frame body, wherein the first weight is connected to thesheave, and either the sheave or the first weight is connected to theframe body through the elastic body arranged on the sheave or the firstweight.
 7. The balancing apparatus of claim 3, further comprising asheave rotatably arranged in the frame body, wherein the first weight isconnected to the sheave, and either the sheave or the first weight isconnected to the frame body through the elastic body arranged on thesheave or the first weight and the damper juxtaposed to the elasticbody.
 8. The balancing apparatus of claim 1, wherein at least one of thefirst weight and the second weight is formed by a lamination of weightmembers.
 9. The balancing apparatus of claim 1, further comprising aslide member or a rotating member interposed between the frame body andthe first weight and able to be moved up and down due to expansion andcontraction of the dynamic vibration absorber.